Her gorgeous mix of glamor, gams and giggles makes Nona Gaye the stuff that love songs are made of. Playing pop muse, however, is not enough for the 18-year-old daughter of the late R&B legend Marvin Gaye. She has turned balladeer herself, and while her single, "The Things That We All Do for Love," climbs up the R&B charts, she occasionally slinks down runways as one of Giorgio Armani's top mannequins. "Singing is my first love," says Gaye, who lives in Redondo Beach, Calif., with her manager-mom, Jan, 37, and brother Frank, 17, "but modeling is fun. It lets me unwind." That there are a full 70 inches of her to unwind was once a source of consternation to the Californian, who literally outgrew her early dreams of becoming a ballerina, an ice skater and a gymnast. But Gaye admits that height wasn't a total hindrance. "I was chubby when I was little," she says. "Then I got taller, and it evened out. Luckily, I have a good metabolism." She also has hypnotic, almond-shaped eyes ("my best feature") and, says Armani, "tenderness and vitality." Although she has had only "maybe three" boyfriends, Gaye is currently involved with an "interesting" man she won't name. "I hope," she says, "our relationship progresses." Meantime, her talent seems unstoppable. "When I first met Nona, she was a delicate beauty who had the world at her feet," says actor Michael Douglas, who co-owns Gaye's record label, Third Stone. "A year later, she's developed into a performer whose sound matches her beauty." As her dad once sang, "Ain't nothing like the real thing."